CN1788140B - Expandable rock bolt and rock bolt system - Google Patents

Abstract

The present invention is related to a rock bolt (7), expandable by means of a pressure media, for insertion into a borehole. The expandable bolt (7) comprises a connection unit (8) with means (11) for detachable interaction with an expansion means (10) for expansion of the rock bolt (7), as well as with a suspension element (16). The connection unit is designed with such external dimensions so that it may be inserted into the borehole. The invention also relates to such a rock bolting system.

Description

Expandable rock bolt and rock bolt system

technical field

The present invention relates to expandable rock bolts for suspension installations.

Background technique

In tunnels and in mines, it is often necessary to suspend different devices used in the work, such as fans, drilling equipment, etc. Additionally, in mines and in tunnels, platforms are often used for conveying excavated and other materials. These platforms are suspended from the roof of the tunnel or mine shaft, eg the above can be done by installing beams in the roof and then fixing the platforms to the beams.

To secure these devices, such as the service platform, to the top, various bolts are used. One often uses expandable bolts, so-called expansion bolts, where the bolt comprises a tube whose interior is pressurized by a pressure member, such as a high-pressure fluid, and thereby expanded. An example of such an expandable bolt is shown in Swedish patent no. 7902129-1. Expansion bolts can be used with specific bindings secured to the expansion bolts. Platforms or devices that people want to hang from the top are then secured in these bindings.

A disadvantage of using these bolts as suspension means is that they protrude substantially from the roof of the tunnel together with certain suspension joints and must therefore be cut and/or covered with a thick layer of stucco cement. This is a costly and time consuming operation and it is desirable to minimize it. In the safety assessment, this bolt with suspension will not be classified as a support for the rock.

Contents of the invention

The object of the present invention is to provide a rock bolt that solves the above problems. More specifically, it is an object of the present invention to provide an improved rock bolt for suspension, which is subjected to minimum stress concentrations in the bolt. Another object of the present invention is to provide a suspension that simplifies the work when moving into rock.

These and other objects according to the present invention are achieved by a rock bolt system to which the first aspect of the invention relates. In the present invention, a rock bolt system includes an expandable rock bolt that is inserted into a borehole and is expandable by a pressure medium and includes a connecting unit, an expansion member for expansion of the rock bolt, and a A suspension element interacting with a connecting unit of the rock bolt, wherein the connecting unit of the rock bolt is designed to have external dimensions such that it can be inserted into a borehole, characterized in that,

The connection unit includes means for detachably interacting with the expansion member and with the suspension element connectable to the rock bolt, and the connection unit includes a support sleeve surrounding at least part of the seat of the connection unit, the support sleeve It is braced against the borehole wall and thus prevents any undesired angular displacement between the connection unit and the remainder of the rock bolt.

According to the invention, the above object is achieved by providing an expandable rock bolt capable of being expanded by a pressure medium, having a connection unit comprising means for interacting with components of the expandable rock bolt and suspension elements. The connection unit is further designed with external dimensions that can be inserted into the borehole. Thereby a suspension is provided which gives less protrusion from the rock and provides better strength.

According to a preferred embodiment, the connection unit comprises a connection sleeve fixed to the rock bolt. Thereby a practical and easy to use connection of the suspension element and the expansion member, respectively, is provided. The connecting sleeve can be inserted into the borehole and thus provides a covering in the tunnel with minimal protrusion from the rock, which leads to faster and more efficient tunneling.

According to another preferred embodiment, the connecting sleeve can be welded to the rock bolt, which gives a safer and at the same time economical and practical connection of the connecting sleeve to the rock bolt.

According to another preferred embodiment, the connecting sleeve of the connecting unit comprises means against which the rock plate can be butted, such as a flange. This gives the rock bolt according to the invention rock supporting properties, whereby the rock bolt comprises two important and useful functions, namely rock supporting and suspension within the same rock. The rock slabs can be further selected as appropriate and depending on requirements, and can eg comprise regular flat rock slabs or eg hemispherical rock bolts. According to this aspect of the invention, the expandable rock bolt can thus be used both as a rock support and as a suspension. Thereby, the total cost of providing the suspension device and the rock support can be reduced, providing an economical solution.

According to another preferred embodiment, the connection unit comprises a support sleeve surrounding at least part of the seat of the connection unit. Due to the fact that the bolt rests against the hole wall, the rock bolt is thereby prevented from being exposed to bending moments.

According to another preferred embodiment, two rock bolts can be combined and thereby provide a longer rock bolt. The rock bolt according to the invention can alternatively be used only as the outermost part protruding from the rock, whereby expandable rock bolts, which usually exist equally or differently on the market, can be used in The deepest part of the borehole.

According to another preferred embodiment, the suspension element may comprise one of: a mounting lug, a single hook, a double hook or a combination thereof. This provides great flexibility and the suspension elements can be adapted as required.

The present invention also relates to a rock bolt system comprising an expandable rock bolt as above, an expansion joint and a suspension element, whereby advantages corresponding to those described above are obtained.

Further advantages are obtained by the different aspects of the invention and will become apparent from the detailed description below.

Description of drawings

Figure 1 shows a rock bolt according to the invention.

Figure 2 shows the rock bolt of Figure 1 provided with a detachable expansion joint according to the invention.

Figure 3 shows the rock bolt of Figure 1 where the removable expansion joint has been replaced by a mounting lug.

Figures 4a and 4b show a second embodiment of a rock bolt according to the invention provided with a detachable expansion joint and a mounting lug, respectively.

Figure 5 shows two rock bolts according to the invention already connected.

Detailed ways

As mentioned above, it is often necessary to suspend different devices in mines or in tunnel work. In rock drilling some kind of rock support is required, such as rock bolts, cables or other elements, in order to strengthen and stabilize the rock and thereby make it self-supporting. As described in the introduction, there are expandable, tubular rock bolts that can be used for this purpose, see eg Swedish patent nos. 427764 and 443398.

The present invention provides improved rock bolts which can also be provided with suspension means giving minimal stick out, and at the same time provide a way of combining these two requirements that exist in rock drilling environments, such as in mines, In the same rock bolt.

Referring now to Figure 1, there is shown a rock bolt 7 in accordance with the present invention. The expandable rock bolt 7 via a pressure medium comprises a connecting unit both for connecting the expansion member 10 (see FIG. 2 ) and for connecting the suspension element 16 (see FIG. 3 ). This connecting unit preferably comprises a connecting sleeve 8 with a seat comprising an inner part 11 for simultaneously receiving an expansion member 10 for expanding a rock bolt 7 and a suspension element 16 . The inner member 11 of the seat can for example comprise a thread, whereby the expansion member 10 and the suspension element 16 respectively can be screwed onto the rock bolt 7 . Alternatively, as shown in Figures 4a and 4b, the connecting sleeve 8 may alternatively comprise external threads for interacting with the expansion member 10 and the suspension element 16, respectively. This must however be done without substantially elongating the rock bolt protruding from the rock, eg such that the sleeve-like portion of the expansion member 10 and the suspension member 16 are of a size such that they can be inserted into the borehole. Other suitable detachable connections are also acceptable.

The connection unit preferably also comprises a support sleeve 9 fixed to the rock bolt 7 . The parts of the connection unit, namely the connection sleeve 8 and the support sleeve 9 in this given case, may be integrated in an alternative embodiment. Furthermore, the support sleeve 9 prevents any undesired angular displacement between the connection sleeve 8 and the remainder of the rock bolt 7 thanks to the fact that the sleeve is supported against the hole wall.

In Fig. 2, the expansion member 10 is shown in the form of an expansion joint, but in other embodiments the expansion member 10 is for example a simple, straight tube or a hollow cable. The function of the expansion member 10 is to allow the expansion of the rock bolt 7 and thus the anchoring of the rock bolt 7 in the rock 12 . Expansion only requires that the expansion member 10 comprise some kind of hollow body through which eg water can be fed under high pressure whereby the rock bolt 7 expands to abut the borehole. The expansion joint is advantageous in that pressurization can be performed subsequently through the radial injection tube, thereby facilitating manual pressurization.

The expansion member 10 preferably fits into a common standard chuck for rock bolts used in rock bolting, and thus no specially designed chuck is required for the rock bolt 7 according to the invention.

In the illustrated embodiment, the connecting sleeve 8 includes a flange 13 where a rock plate 14 abuts. Other members than flanges are also acceptable as support for the rock slab 14 . By the fact that the rock plate 14 can be used in combination with the rock bolt 7, the rock bolt 7 can also be used as a support for the rock, which is not possible with prior art suspensions. The rock slab 14 may be a plain flat plate or may be hemispherical, as shown in the figures.

When the rock bolt 7 has been expanded by means of the expansion member 10, which has been connected to a source of pressure medium not shown, the expansion member 10 can be unscrewed. This provides a rock bolt that gives little sticking out. Referring to Figure 3, suspension elements 16 can also be attached if desired. The rock bolt 7 can thus be used, for example, as a suspension for a service platform or the like. The suspension element 16 is provided with means for interacting with the inner (or outer) member 11 (eg thread) of the connecting sleeve 8 . In FIG. 3, the suspension element 16 is shown in the form of a mounting lug, but in alternative embodiments, the suspension element 16 may comprise any suitable suspension member, such as a single hook, double hooks, hooks, or any combination of these. This provides a flexible suspension that can be adjusted as required.

Also, the suspension elements 16 can be unscrewed and reused as the tunnel progresses. This gives at least two advantages. Firstly, the cost of the suspension element 16 is reduced since the suspension element 16 can be used several times. Second, the smaller protrusion from the rock eliminates the need to cut the bolt after use, which is otherwise a time-consuming process. Thereby, the production process is accelerated and the required thickness of covering with stucco cement or the like is reduced, which again reduces costs. With only a few components that are simply assembled, further installation is quick.

As shown in Figure 5, the connecting unit can be adjusted so that two and more rock bolts 7', 7" can be joined together to form a long bolt. This can be done in different ways. If one wants to combine two rock bolts according to the present invention Two rock bolts 7', 7" are combined, and the outer rock bolt 7' has to have a through cable with a connection joint 17, which is combined with the connection sleeve 8 on the inner rock bolt 7". The application of pressure medium outside the hole achieves expansion of both bolts 7' and 7".

The inner part of the rock bolt 7 can alternatively be replaced by an outer mount which is joined together with a conventional expandable rock bolt. The rock bolt 7 according to the invention is only used as the outermost part protruding from the rock, whereas the regular joint expandable rock drill bit is used at the deepest part of the rock 12 .

Claims (10)

1. rock bolt system, comprise and be used to insert in the boring and expansible and comprise the expandable rock bolt of linkage unit by pressure medium, the expansion (10) that is used for the expansion of bysmalith, and be used for and the interactional hanging element of linkage unit (16) of bysmalith (7), wherein, the linkage unit that designs this bysmalith has makes it can insert the external dimensions in the boring, it is characterized in that

This linkage unit comprise be used for expansion (10) and with the removably interactional member of hanging element (16) (11) that can be connected on the bysmalith, and this linkage unit comprises around the stop sleeve to small part (9) of the seat of linkage unit, and this stop sleeve (9) relatively drill hole wall supports and therefore prevent any angular displacement of not expecting between the remainder of linkage unit and bysmalith.

2. rock bolt as claimed in claim 1 system is characterized in that this linkage unit comprises the branch sleeve (8) that is fixed on the bysmalith (7).

3. rock bolt as claimed in claim 2 system is characterized in that branch sleeve (8) comprises rock panel (14) butting member of its butt joint (13) relatively.

4. rock bolt as claimed in claim 3 system is characterized in that, expansion (10) comprises the joint that can insert in the linkage unit.

5. rock bolt as claimed in claim 3 system, wherein, described butting member is flange (13).

6. rock bolt as claimed in claim 2 system is characterized in that, expansion (10) comprises the joint that can insert in the linkage unit.

7. rock bolt as claimed in claim 1 system is characterized in that this linkage unit is fixed by welding on the bysmalith (7).

8. rock bolt as claimed in claim 1 system is characterized in that, expansion (10) comprises the joint that can insert in the linkage unit.

9. rock bolt as claimed in claim 1 system is characterized in that, bysmalith (7 ') provides the jointing on inside (17) that connects pipeline and be used to connect second bysmalith (7 ").

10. rock bolt as claimed in claim 1 system is characterized in that hanging element (16) comprising: patchboard, single hook, double hook or their combination are installed.

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